The present invention relates to a signal synthesizer system allowing a wide variety of signal sources for test and evaluation, and more particularly relates to a two channel signal synthesizer system having a variety of capabilities to generate a wide range of complex signals.
Most signal synthesizer systems provide precision waveforms of signals with frequency accuracy and resolution for test and evaluation of electrical measurement. For example, a single channel synthesizer system can be synthesizer, function generator and sweep generator providing sinewaves and square, triangle and ramp waveforms for use. As a synthesizer, the single channel system provides waveforms with precise frequency. As a function generator, the synthesizer system provides a variety of waveforms including sine, square, triangle, and ramp. As a sweep generator the synthesizer can sweep over a range of frequencies. However, there is a high demand for much improved performance of the synthesizer system in spectral purity, phase noise and phase accuracy. Furthermore, it is important to provide the synthesizer system with a variety of additional capabilities.
In the case of providing two calibrated phase outputs, a function generator can be phase locked to an external reference signal, and provide an output signal of the same frequency and variable phase offset. But these kind of phase lock generators have several disadvantages in regard to phase accuracy, phase resolution, frequency range and manual operation.